Electric switch gear



Jan. l7, 1933. c. s. AGATE ET AL ELECTRIC SWITCH GEAR Filed Sept. 8, 1930 Patented Jan. 17, 1933 UNITED STATES PATENT OFFICE CHARLTON STANFORD AGATE, OF SOUTH CROYDON,

AND WILLIAM ALFRED JAMES THORN, OF LONDON, ENGLAND, ASSIGNOBS TO COLUMBIA PHONOGRAPH COMPANY, INC., OF BRIDGEPORT, CONNECTICUT, A CORPORATION OF NEW YORK ELECTRIC SWITCH GEAR Application filed September 8, 1930, Serial No. 480,440, and in Great Britain September 26, 1929.

This invention relates to electric switch gear and has more particular although not exclusive reference to electric switch gear for use in connection with wireless receiving sets, electric phonographs or in connection with combined wireless receiving sets and phonographs.

Hitherto in connection with such instruments the problem has arisen of connecting circuits in a variety of ways by means of suitable switch gear and for this purpose a simple type of selector switch has invariably been employed. Such apparatus has, however, been almost exclusively driven from sources of supply only capable of delivering small amounts of power, for example, dry or other batteries. It has therefore been possible to use simple and cheap types of switch gear which were capable of dealing with the relatively small power utilized in the circuit. Such switches are, however, quite unsuitable for breaking circuits in which an appreciable amount of power is employed as in certain wireless receiving sets or such combined with a phonograph which derive power from a mains supply.

In radio and phonograph amplifier circuits it is often required to change the circuit arrangement by means of a multi-circuit multi-way switch, one or more of the contacts of which are often required to break fairly high voltages and since, for the purpose of compactness and cheapness, these contacts are small they would normally become badly burnt in time while it is also possible that the gap between the contacts when open would not be sufficient to break the are formed on breaking the circuit. There is also a possibil ity that undesired circuit combinations are made in an intermediate position of the switch.

The object of the present invention is to provide improved switch gear for use particularly in connection with the apparatus referred to above and the invention consists in a selector or local circuits switch combined with means such as will prevent the selector switch from being operated until after the main power circuit has been broken so as to ensure that no sparking may occur during the operation of the selector switch.

The invention also consists in electrical switch gear comprising a local circuit or selector switch and a main power switch preferably of the quick-break type and means whereby the selector switch cannot be operated until after the power circuit has been opened by the main switch.

According to a preferred form the two switches are intercoupled by providing the main power switch with an extended part which is adapted to project into and lock the selector switch, such projecting part being automatically withdrawn upon the mains switch being opened.

The accompanying drawing illustrates one convenient form of switch gear in accordance with the invention.

In carrying the invention into effect according to one convenient mode as applied by way of example to a combined wireless receiving set and phonograph, we provide a local circuit or selector switch of any convenient form which is adapted to connect the circuit in a variety of ways, for example, to disconnect the phonograph section of the apparatus from the wireless receiving section or vice versa.

According to the embodiment illustrated such selector switch comprises a plurality of contacts adapted to be opened and closed by studs 6 or other excrescences so placed upon a drum or cylinder 7 that the desired circuits are made in each switch positions and these positions may be defined by a spring-controlled ball stop 8 or other means.

The power switch as before stated is preferably of the quick-break type and may comprise a spring-controlled switch tongue 9 operated by the switch arm 10 to which is connected a plunger 11 adapted to be reciprocated upon the opening or closing of the switch.

The plunger 11 co-operates with one or other of the apertures or recesses 12 in the drum 7 of the selector switch so that the latter may be locked in its various selected positions when the main supply circuit is closed and the selector switch cannot be thus operated until the main supply circuit has been broken when the plunger 11 will then be withdrawn from the aperture or recess. It will be appreciated that the selector switch is provided with an aperture or recess 12 for each position into which such switch may be moved.

It will be seen, therefore, that we have provided an effective means for preventing the operation of the selector switch whereby any objectionable sparking that may occur between the various contacts of the selector switch is avoided by the provision of the coupling between the two switches which permits working of the selector switch only when the main power circuit is open.

According to a further form'of the invention, instead of providing a mechanical couple between the two switches, an electrical couple may be employed. For example, upon the A closing of the main power circuit, such circuit may be caused toenergize a solenoid or other device in such a manner as to lock the selector switch in any of its desired positions with the result that the selector switch cannot thereafter be operated until the main power circuit is broken whereupon the solenoid is de-energized, permitting the selector switch to be operated.

It is to be understood that the invention is not to be limited to the above details of construction since we may vary the construction of the selector switch and also the construction of the main power switch and the arrangement of the solenoid in the main power circuit depending upon any practical considerations that may have to be fulfilled.

Having now particularly described and ascertained the nature of our said invention and in what manner the same is'to be performed, we declare that what we claim is In an electrical switch gear, a selector switch including a rotary cylinder having contact closing studs thereon, said cylinder adapted to be moved to position said studs in their various circuit closing positions and having a series of radially arranged openings the number and positions of which correspond with the various positions into which the cylinder may be moved in the operation of the selector switch, a main power switch, means including a slidable bolt operable by the main power switch to and from looking position, and said bolt adapted to be moved to enter one of said radial openings to lock the selector switch against movement on the main switch being moved to circuit closing position.

Signed at London, England, this 21st day of August, A. D. 1930.

CHARLTON STANFORD AGATE. WlLLIAM ALFRED JAMES THORN. 

